While there is a growing demand for the bandwidth offered by 10G Ethernet to connect buildings, floors and even servers to each other, it is also likely that new ways of using existing applications will ride on the back of the faster cable plant. There will also be new applications arising which were dismissed as too hard or too expensive before the advent of 10G Ethernet.
When the whole world comes to regard video-on-demand as a normal service, much like the telephone lines of old, the pipes will need to carry 1Gb links at the very least, and that will require 10Gb pipes, at the very least, to provide the aggregate upstream feeds. Feature-length high-definition movies won't be popular downloads if customers have to order them two days before they want to watch.
Another application methodology that's been on the wish list at many companies is the concept of the server-less building. Many quite heavy users of IT don't see the real value in being IT experts themselves. They'd much rather buy their IT requirements off the shelf, and sit their staff in front of a screen, the way things used to be back in the begging of computing. However, what's really stopped this methodology from achieving major market share has been the massive, and expensive, bandwidth required to present today's rich graphical experience remotely, despite the venerable efforts of companies such as Citrix.
With a 10G Ethernet feed into the building, and 1G Ethernet feeds to the users' screens, it really will no longer matter where the server lives, or indeed who owns it and cares for it, as long as it is available when required. If you haven't thought much about hosted servers, your opportunity to do so may be short-lived. In the very near future there will probably be no other kind.